Because of their composition, cosmetic agents can be a nutrient medium for bacteria and microorganisms. These bacteria, on the one hand, can cause the microbial contamination of the user, and, on the other, they can change the ingredients of the cosmetics and thereby form substances with undesirable effects such as sensitization or skin irritation. In order to prevent these undesirable consequences and to assure a specific minimum durability of the cosmetics, they must be preserved. Because preservative for their part have an irritation potential, their use in cosmetics is strictly regulated.
Skin microflora has a decisive effect on various cosmetic parameters. Thus, pathogenic bacteria such as Staphylococcus aureus play a decisive role in the formation of skin impurities. Most recent studies also point out that an unbalanced skin microflora can exert an effect on skin aging, because undesirable bacteria can lead to an increased immune defense of the skin, which in turn leads to increased inflammatory reactions during which skin aging markers are stimulated.
There continues to be a need for preservative compositions, therefore, that, on the one hand, prevent the colonizing of the product or skin with undesirable bacteria and, on the other, do not or do not substantially affect the natural skin flora.
The mixing of different antimicrobial substances to increase the antimicrobial activity is generally known. Thus, WO 03/043593 A1 proposes combining conventional antibacterial substances such as triclosan, phenoxyethanol, or hexetidine with ethyl lauroyl arginate to enhance the antibacterial action. In WO 2007/014580 A1, preservative mixtures are proposed, which, include, apart from ethyl lauroyl arginate salts of organic or inorganic acids, in particular sodium citrate, sodium acetate, sodium glutamate, sodium fumarate, sodium malate, sodium gluconate, sodium laurate, sodium lactate, sodium hexametaphosphate, sodium tert-butylhydroquinonate, sodium propylparabenate, or the hydrochlorides of glucosamine or ethanolamine. Cosmetic compositions, which include a preservative mixture of ethyl lauroyl arginate and parabens, imidazolyl urea, phenoxyethanol, DMDM hydantoin, 2-methyl-5-chloro-3,4-isothiazolinone/2-methyl-3,4-isothiazolinone, and quaternium-15, are disclosed in EP 1414394 B1.
Therefore, there continues to be the need for providing antimicrobial compositions that are highly effective when used in a low amount.
To summarize, it is desirable to provide cleansing compositions that have an excellent cleansing and care effect with simultaneously good preservation. In particular, it is desirable to provide synergistic preservative mixtures that are highly effective in low concentrations, and because of their overall reduced quantities enable the production of low-irritant and low-sensitizing cleansing compositions. Furthermore, no preservatives critically perceived by the consumer should be used. Moreover, the foam quality, foam quantity, and lather amount should not be negatively influenced by the addition of the preservative mixture to a cleansing composition.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with this background of the invention.